The length is approximately 40cm, excluding the clasp. The material is unknown, but it's a beautiful and refreshing necklace, like beads or crystals. The largest part is 1cm in diameter, and the smallest part is 4mm in diameter. Each design is lovely, so please take a look at the last photo. The clasp is a screw type. It's been stored for a while, so the clasp is a little tarnished, but the necklace itself is very clean. We look forward to your purchase if you don't mind this. If you like it, feel free to comment! (^-^)/